Now that we’ve looked at the overview of
calcium homeostasis, let’s take a look at
hypercalcemia and all the different pathologies
associated with it.
Abnormal elevation of serum calcium, first
step, workup is to confirm the elevation and
always check to see as to what your free ionized
calcium is because that would be the functioning
Calcium is 40 percent bound to albumin, it
requires a chaperone.
Remember, overall calcium in-in the ECF is
a very, very small percentage; 99 percent
of your calcium is actually in your bone.
Remember that calcium and majority of it,
in fact, is in ECF.
Therefore, any time a... any type of... any
time there’s a channel that’s opened up
for calcium, it will then rush in.
Adjusted total calcium, what does total mean
The bound plus the free or the ionized; always.
What is it that makes majority of your total?
It’s the bound.
Adjust total calcium up to 0.8 milligrams
per decilitre for every gram by which serum
albumin is below 4 grams per decilitre.
Alkalosis increases calcium binding to albumin
whereas acidosis decreases it and that’s
an important point.
At some point in time, we’ll talk more about
acidosis and the activity of osteoclasts and
so forth, but at this point, understand that
alkalosis increases calcium binding to albumin.
The more they’re positive, cation calcium
will bind to albumin when there’s alkalosis
state in your plasma.
Hypercalcemia acute, what kind of issues might
the patient then have?
Anorexia, nausea, vomiting, constipation.
CNS, there will be confusion and weakness,
hyporeflexia versus tetany.
There is no muscle twitching in hypercalcemia,
none; if anything hyporeflexia.
Cardiovascular, hypertension, shortened QT,
not lengthened; occasional brady and maybe
perhaps first degree AV block, you’re looking
for prolonged, permanent prolongation of your
In the kidney, maybe associated with polyuria,
polydipsia, especially if you’re thinking
about nephrogenic diabetes insipidus and
prerenal azotemia, decreased
filtration resulting in hypocalcemia.
These are issues that you’re looking for
clinical manifestations of hypocalcemia.
Chronically, the pneumonic that you have probably
come to become familiar with: stones, bones,
groans and psychic overtones, pretty much
tells you the problems that you would have
with chronic hypercalcemia.
Stones, calcium stones, being the most common,
calcium oxalate; bone issues groans, pain
and psychic overtones; osteoporosis with bone
pain, nephrocalcinosis with stones.
It will be band keratopathy, deposition of
calcium-phosphate in sun-exposed cornea…
You have chondrocalcinosis, meaning to say
that in the bone by the epiphyseal plate,
you’d have accumulation of calcium... calcium,
hypercalcemia may actually bring about damage
to the pancreas.
You’ve heard of saponification and may cause